1. Field of the Invention
This invention relates to methods and apparatus for closing apertures in human and animal tissue and to methods and apparatus for inserting apparatus into such tissue to perform such closure functions.
2. Description of the Prior Art
During certain types of vascular surgery, catheters are inserted through an incision in the skin and underlying tissue to access the femoral artery in the patient's leg. The catheter is then inserted through the access opening made in the wall of the femoral artery and guided through the artery to the desired site to perform surgical procedures such as angioplasty or plaque removal. After the surgical procedure is completed and the catheter is removed from the patient, the access hole must be closed. This is quite difficult not only because of the high blood flow from the artery, but also because there are many layers of tissue that must be penetrated to reach the femoral artery.
Several approaches have used to close femoral access holes. Typically, manual compression by hand over the puncture site can be augmented by a sandbag or weight until the blood coagulates. With this approach it can take up to six hours for the vessel hole to close and for the patient to be able to ambulate. This increases time for the surgical procedure as well as overall cost of the procedure since the hospital staff must physically hold pressure and the patient's discharge is delayed because of the inability to ambulate. This is not an efficient use of either the patient's or staff's time. After some procedures, to close the vessel puncture site a clamp is attached to the operating table and the patient's leg; The clamp applies pressure to the vessel opening. The patient must be monitored to ensure the blood is coagulating, requiring additional time of the hospital staff and increasing cost of the procedure.
To avoid the foregoing disadvantages of manual pressure approaches, suturing devices have been developed. One such suturing device, referred to as “The Closer” and sold by Perclose, advances needles adjacent the vessel wall opening and pulls suture material outwardly through the wall adjacent the opening. The surgeon then ties a knot in the suture, closing the opening. One difficulty with this procedure involves the number of steps required by the surgeon to deploy the needles, capture the suture, withdraw the suture, and tie the knot, and cut the suture. Moreover, the surgeon cannot easily visualize the suture because of the depth of the femoral artery (relative to the skin) and essentially ties the suture knot blindly or blindly slips a pre-fabricated knot into position. Additionally, the ability to tie the knot varies among surgeons; therefore success and accuracy of the hole closure can be dependent on the skill of the surgeon. Yet another disadvantage of this suturing instrument is that the vessel opening is widened for insertion of the instrument, thus creating a bigger opening to close in the case of failure to deliver the closure system.
It would therefore be advantageous to provide an instrument which quickly and accurately closes holes in vessel walls. Such instrument would advantageously avoid the aforementioned time and expense of manual pressure, simplify the steps required to close the opening, and avoid widening of the opening.